Wikipedia is the definitive source which decides whether teams seeding 65-68 are NCAA tournament participants?
This is from the NCAA website (
https://www.ncaa.com/news/basketbal...-27/first-four-ncaa-tournament-ultimate-guide) and doesn't read like the "First Four" are "play-in" games:
Who plays in the men's First Four?
When selecting the teams for the NCAA tournament, the NCAA Division I Men's Basketball Committee ranks every team from No. 1 through No. 68. In its current format, the First Four consists of eight teams — the four lowest-seeded automatic qualifiers and the four lowest-seeded at-large teams. Each subset plays against itself (i.e., at-large teams face at-large teams, and automatic qualifiers face automatic qualifiers).